Broaching machine



June l8 1940.

M. ROMAINE El AL BROACHING MACHINE INVENTOR..

ATTORNEY.

June 18, 1940. M, ROMAlNE ET AL 2,2059277 l BROACHING MACHINE l0 Sheets-Sheet l2,.

Filed Oct. 27, 1937 www@ mwwm U mm E O WMMW I/.owfm- ,/l www; H, .m n. Hl w U www n U Y B mu. U n U ,U IIHUII V uw June 18, 1940. M. ROMAINE Ei- AL BEOACHING MACHINE Filed'oct. 2v. 1957 1o sheets-sheet s June 33 1940 M. ROMAINE E1- Al.

BROACHING MACHINE 10 Sheets-Sheet 4 Filed Oct. 27. 1937 ,f6 Z1/a5 w w g ATTORNEY.

M. ROMAINE Er AL BROACHING MACHINE Filed OGL 27. 1937 l0?) l0 Sheets-Sheet 5 /f\\ "T`TT L l INVENTOR.

June 1s, 1940. M. ROMAN; ET AL 2,205,217

BROACHING MACHINE Filed om. 27, 1937 1o sheets-sheet s Vi/ATTORNEY.

June 18, 1940. M. ROMAINE ET AL 2,205,277

BROACHING MACHINE Filed Oct. 27A 1937 10 Sheets-Sheet 8 ATTORNEY.

June 18, 1940. M. ROMAINE ET AL 2,205,277

BEOACHING MACHINE Filed oct, 27, 19:57 '1o sheets-sneer 9 v TTORNEY.

June 1s, 1940.

M. ROMAINE ET AL BROACHING MACHINE Filed Oct. 27. 1957 10 Sheets-Sheet 10 ATTORNEY.

Patented June 18, 1940 BaoAoHlNG MACHINE Millard Romaine, Amos H. Hawley, and Herman Horlacher, Cincinnati, Ohio, assignors to The Cincinnati Milling Machine Co., Cincinnati, Ohio, a corporation of Ohio Application October 27, 1937, Serial `No.l 171,372

21 Claims.

This invention relates to machine tools and more particularly to improvements in breaching machines.

One of the objects of this invention is to imv prove the eiciency of surface broaching machines by arranging the work holders and tools in such a manner that breaching can be effected during both directions of ram movement.

Another object of this invention is to provide improved means for handling work at a broaching machine, whereby both sides of a work piece may be broached sequentially in a machine.

A further object of this invention is to provide an improved swinging work holder whereby the momentum of the work and holder during retraction from the broach is utilized to store energy for clamping the next work piece.

Other objects and advantages of the present invention should be readily apparent by reference to the following. specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and de- 26 scribed, within the scope of the appended claims, without departing from or exceeding the ,spirit of the invention.

Referring to the drawings in which like reference numerals indicate like or similar parts:

Figure 1 is an elevation of a broaching machine embodying the principles of this invention.

Figure 2 is a section on the line 2 2 of Figure 1.

Figure 3 is a detail section on the line 3 3 of Figure l showingthe work transfer cradle. y

Figure 4 is a section on the line A li .of Figure 3.

Figure 5 is a section through the lower work holder as viewed on the line 5 5 of Figure 2.

Figure 6 is a section on the line E of Figure 5.

Figure 7 is a plan view of the lower work holder 4U as viewed on the line I 'i of Figure l.

Figure 8 is a detail section on the line 8 8 of Figure 7.

Figure 9 is a detail section taken on the line 9 9 of Figure 1 showing the work holder locking mechanism. Y

Figure l is a detail section on the line iB i of Figure 9.

Figure l1 is a. diagrammatic View of the hy- .du draulic actuating and control circuit for the broaching ram.

Figure l2 is a diagrammatic view of the hydraulic control ,circuit for governing movement of the work holders and 'worktransferring mech- 55 anisms. y Y

Figure 13 is a section of the lower work holder taken on `the line !3 I3 of Figure '7.

. Figure 14 is an end elevation of the lower work holder showing same advanced to a 45 position.

Figure 15 is a View of the left work transferx mechanism. K

Figure i6 is a section of the left, or upper, work locking mechanism. f

Figurel 17 is a View on line` H ill of Figure 16. Figure l8is a view on line iB i of Figure 16. 10 Figure 19 is a view on line ltrl of Figure 16. Figure 2.0v is a sectional View of the backing-up plungers incorporated in the left, or upper, work holder.

Figure 21 is a sectional view through the work1115 end stop of the upper work holder.

Briey, this invention Lcontemplates a horizontal type of surface breaching machine having a reciprocating cycle in the sense that breachingV takes place in both directions of ram movement, together with separate fixtures for holding the work for the respective directions of breaching and a transfer mechanism located between the ,fixtures having the capacity for reversing the work when transferred from one xture to the V25 other whereby opposite faces of a work piece may be broached sequentially in the machine.

Referring to Figures l, 2 and 1l, the reference numeral IE? indicatesthe bed of the machine upon which is formed a pair of guide ways H and i2 `30 for supporting and guiding a broachilig ram i3 for horizontal movement. As shownin Fig'- ure 2, the breaching ram has a first or lower broaching tool M secured to the Vertical face iii of the ram and a second or upper breaching tool ,It secured to the vertical facej of the ram, but in offset relation thereto as more particulariy shown in Figure l. In other words, the broaching tools overlap one vanother in the central portionof the ram, but each has a portion eX- y tending beyond the end of the other. Due to the nature of the work, the broaching tool M has .a divided cutting face, or, in other words, has two sets Il and I3 of cutting teeth, while the broach I B has cutting teeth i9 and 2'arranged .at right angles to one another, andan additional setof cutting teeth 2l aranged at an angle to the planevof the teeth 2d. It will be obvious that the arrangement of teeth on each breaching tool could be varied` tosuit the nature of the work without departing from the principles of this invention. y

The lower breaching tool is provided for vbreaching work mounted in the lower oscillatable workholder 22 which is located on the right side 5,5

v controlled reversing valve 32.

of the machine as shown in Figure 1, and the upper broaching tool is for broaching work carried by the upper oscillatable work holder 23 located on the left side of the machine. The teeth on the two sets of broaching tools are so arranged that they cut while moving in a direction toward the center of the machine and the two sets of broaching tools overlap one another a sufficient amount that when the end of the upper broaching tool I6 has just passed the right hand end of fixture 23 the lower broach tool I4 has just passed the right end of fixture 22 so that upon reversal of the ram the tool |4 is ready to begin cutting. The same thing is true at the other end of the stroke, that is, when the breaching tool I4 has completed its movement past xture 22, the broaching tool `I6 is in a position to begin cutting from the left hand of fixture 23. The hydraulic circuit and control mechanism for effecting relative movement between the tools and work is shown in Figure 11. In the present machine the hydraulic cylinder 24 is formed integral with the ram I3 and the contained piston 25 is held stationary by virtue of connecting both piston rods 26 and 21 to the bed |0 of the machine. Hydraulic connections are emected to both ends of the cylinder by means of axial holes formed in the piston rods which intersect diametric holes adjacent each side of the piston 25.

Fluid is supplied to opposite ends of the cylinder through channels 28 and 29 which are connected to ports 30 and 3| respectively of a pilot This valve has a central pressure port 33 which is supplied with fluid through channel 34 by a series of pumps 35 which withdraw fluid from a reservoir 36'. This valve also has a pair of exhaust ports 36 and 31 which are connected to a return channel 38.

When the valve plunger 39 is in the stop position in which it is shown, the pressure port 33 is closed and the motor ports 30 and 3| are isolated, whereby no movement of the ram can take place, but due to the large volume of oil that is being supplied by the pumps 35, means are provided in the plunger for by-passing this oil to reservoir freely rather than forcing this oil through a relief valve which would cause excessive heating of the oil. This means comprises an additional port 40 to which the pressure line 34 is connected by a branch line 4| and this port is connected by a cannelure 42 in the plunger to the exhaust port 36. Thus, delivery from the pumps is freely by-passed to reservoir without causing excessive heating thereof.

lWhen the plunger 39 is shifted upward, as Viewed in Figure 11, the pressure port 33 is connected to the motor port 3| and the motor port 30 is connected to the exhaust port 31, whereby matic trip type which when open will connectv the pressure port to reservoir and which will remain open until manually reset by the operator. This valve has a pressure port 34 which is directly and continuously connected to the supply line 34 and this port is connected by an annular groove 45 in the plunger 46 to a passage way 41 which has one branch terminating in a cylinder 49 into one end of which projects the reduced end of plunger 46. From this it will be seen that whatever pressure exists in channel 34 will also exist in cylinder 49 and this pressure will be continuously acting to shift the plunger 46 upward. This movement is normally prevented by a locking plunger 49' which has a portion 50 fitting in a notch 5| cut in the side of the plunger 46.

The valve 48 has a spring 52 to determine the pressure at which the relief Valve will be tripped. When this pressure has been reached the valve 48 will open and iiuid will enter channel 54 which has one branch terminating in a cylinder and the other branch connected to a hydraulic if resistance 56, the other end of the resistance leading to reservoir. The sudden admission of high pressure into channel 54 will not escape immediately to reservoir due to the resistance 56 and pressure will immediately build up in the nelure 45 in plunger 46 will then be in a position to connect port 44 to port 58 which is connected by channel 59 to the annular groove of exhaust port 31 whereby the uid may be freely returned to reservoir.

When the emergency has passed the operator pushes on the upper end of the plunger 46 to relatch the same in the position shown.

The reversing valve plunger is hydraulically shifted into any one of its three positions and to this end the opposite ends of the housing are provided with cylinders 60 and 6| which are connected by channels 62 and 63 to ports 64 and 65 respectively of a pilot valve 66. A tubular plug 61 forms the inner end of each cylinder and a hanged bushing 68 is-slidably mounted in the plug and the bushing is of such length that when pressure is admitted to both cylinders and the flanged ends of the bushings abut the ends of the plug as shown, the inner ends of the bushings will abut both ends of the plunger 39 and thereby move it and hold it in a central position.

The plunger 39 has reduced ends 69 which pass centrally through the bushings whereby when pressure is relieved in one cylinder the pressure acting on the other reduced end of the plunger will shift the plunger as well as the bushing to one of its extreme positions and thereby effect an operative connection to the cylinder.

The pilot valve 66 has a pressure port 10 to which fluid is supplied by a pump 1|. When the pilot valve plunger 12 is in a central or stop position the pressure port 1|] is connected by cannelure 13 in the plunger to both ports 64 and 65, whereby pressure is admitted to both cylinders 6l) and 6| of the reversing valve and the plunger 39 is moved to a central position. When the plunger 12 is shifted to the right of the position shown, the port 10 remains connected to the port 64, while the port is connected by a cannelure 14 to exhaust port 15 whereby the reversing valve plunger 39 is shifted upward. When the plunger 12 is shifted to the left the pressure port 10 re-4 mains connected to the port -|55 and the port 64 is connected by cannelure 16 to exhaust port 11 with the result that the plunger 39 is shifted downward.

The pilot valve plunger 12 has a ball and socket connection 18 to a lever 19 which is keyed to a shaft 80 having a pinion 8| and an interlock plate 82 also keyed thereto. The pinion 8| meshes (lili keyed to the other end thereof.

with a pair of rack plungers 83 and 84 which are mounted on opposite sides of thepinion, whereby when one moves up the other moves down. These plungers are oset in different planes whereby the trip dog that actuates one will not interfere with the other. A manually operable handle 85 is also keyed to the shaft 86 for shifting the pilot valve plunger in one direction or the other to start the machine, and also serves as an emergency stopping means. As shown in Figure 2, the dogs 86 and 8l which operate the trip plungers 83 and 8e are carried by the dog rail 88 attached to the top of the ram I3.

To prevent the operator from starting the ram moving in the wrong direction, the interlock plate 82 has been provided which has a pair of ears 89 and 98 which cooperate with pivoted bell cranks 9| and S2 respectively. These bell cranks are withdrawn from a lockingposition by iiuid operable plungers 93 and 94 which vare slidably mounted in cylinders 95 and 96 respectively.

These cylinders are connected by channels 9'! and 98 to the circuit shown in Figure l2 which controls the operation of the work fixtures. The

manner in which this interlocking mechanism functions will be described later in connection ith the operation of the Work fixtures.

. Lower work fixture The lower work xtureis shown more particularly in Figures 2, 5, 6 and '7, and as shown in Figure 7, the fixture 22 is provided with two bosses 99 and IDB by whichV it is supported on a shaft |0|. The fixture is oscillated by this shaft,

but a separate driving member is provided for this purpose. As shown in Figure 2, the driving member comprises an annular ringv |02 which has a pair 0f laterally extending ears |83 and lull which engage wear plates |05 and Hl whichare attached to the fixture.v The member |02 is keyed at |01 to the shaft. Attention is invited to the fact that the plates |05 and I [lf3 are for the purpose of forming a sliding connection between the driver |02 and the fixture since the driver is held against longitudinal movement with respect to the shaft, but the fixture is supported on the shaft by its trunnions and I0@ for limited movement relative thereto.

The work pieces, which in the present instance, are cylinder blocks, are fed to the fixture on a conveyor |08, a portion of which is shown in Figure 1. The fixture itself is provided with a drop bottom |09 which is pivotally supported at each end by a pair of links H43 and Ywhich have one end pivotally connected to the bottom |09 and the other end pivotally connected to a xed part of the fixture 22. The link Nil has an integral operating lever H2, in the end of which is mounteda roller |53 for engagement with the periphery of an operating cam l ill. As

shown in Figure 5, the link l l@ is keyed to the end of a shaft H5 and this shaft extends the width of the xture for actuation of link H6 which is it will now be apparent that by rotating. the lever H2 in a counterclockwise direction, as viewed in Figure 2, that the drop bottom |99 will be elevated and upon rotation of the lever in the opposite direction the drop bottom will be lowered. As shown in Figure 7, the drop bottom mi) is provided with a series of rollers for facilitating movement of the work from ,the conveyor 68 into the fixture. When the fixture is down and the drop bottom is elevated the rollers lll' lie in substan.

tially the same plane as the rollers of the con-v veyor. When the work is in position to be clamped in the fixture the drop bottom isA lowered and the work is positioned and held in the fixture by other means.

IIhe mixture is moved clockwise through an angle of 90 degrees from the position in which it is shown in Figure 2 to bring the work to a broaching position. As the fixture returns from the broaching position to the loading position, in

which it is shown in Figure 2, the momentum of the iixture is. utilized to operate a series of plungers whichautomatically unclamp the work and raise it in the fixture ready for removal, and in so doing it compresses springs associated with these plungers whereby upon the next movement to a cutting position the springs are automatically released to effect reclamping of the workwithout attention on `the part o-f the operator.

The first of these plungers is shown in Figure 6 and consists of a rack plunger H8, which upon return movement of the fixture is in a projected position with respect to the fixture as shown in Figure 2, but during counterclockwise rotation of the fixture the roller l IS, which is mounted in the end of the plunger, engages the top edge of a plate |20. As the flxturecontinues to rotate counter-,- clockwise, the plunger is moved inward relative to the fixture and at the same time the roller travels along the top edge of the plate |20. .By the time that the fixture has reached the end of its counterclockwise movement, the roller H9 has cleared the end o-f the plate |20. This upward movement of the plunger causes counterclockwise rotation oi a pinion |2| keyed to a shaft |22, which shaft projects through the fixture and has the cam H4 keyed to the end thereof. This upward movement also causes counterclockwise rotation of a pinion |23 keyed to a shaft |24 which projects through the fixture and has a handle 25 keyed to the end thereof.

Counterclockwise rotation of the cam ||4 rotates the lever ||2 in a counterclockwise direction, thereby raising the drop bottom |09 into the plane of the conveyor I for reception of a new workpiece therefrom. After the new work piece has been positioned in the fixture, the handle |25 is rotated in a clockwise direction to move the plunger I`|8 downward andthereby rof tate the cam H4 in a clockwise direction and permit the drop bottom to fall by gravity.

t will be appreciated that due to the parallel links lll and l l that the bottom not only moves upward but sideways and it' produces the same effect on the work, thereby lifting the same off the positioning members IM which, as shown in Figure 5, is secured by set screws |21 to the rear wall of the fixture. These positioning or locating members are provided with taper bottoms |28 for engagement by tapered surfaces |2 formed on a backing-up or locking member i3@ which is interposed between a shoulder l3| formed on the back wall of the x'ture and the member |26. The member l'll is held in position by set screws |3| which pass through elongated slots |32 formed in the member |30 to permit longitudinal movement thereof, and an adjusting set screw |33 is threaded in the end of the member |30 in abutting relation to a lug |34 whereby upon The members |26 engage the underside of bosses |36 on the work to determine the vertical position thereof. The means for positioning the Work laterally comprise a pair of equalizing plungers |31 and |38, which are shown in Figure '1, and they have their ends cut at 45 degrees for engagement with the ends of an equalizer bar |39.` The ends of the members |31 and |38 are 'cut away on the underside as shown in Figure 6 to form a narrow work engaging surface |39. Since this surface engages the rough edge of the casting,-the provision of equalizing means permits the members |31 and |38 to relatively adjust themselves when lateral pressure is applied on the opposite side of the casting so that the axis of the casting may be lined up in parallel relation to the axis of the xture.

A pair of positive stops or positioning members |40 and |4| are secured to the rear wall of the fixture as by screws |42 and each has an integral finger |43 projecting therefrom for engaging the lower part of the work and positively positioning the same vertically in the fixture. From Figure 6 it will be noted that the members |26 act as a fulcrum about which the work is free to rotate, but the members |31 and |381, which are on one side of the fulcrum, and the members |43 on the other side of the fulcrum prevent this rotation which results in a form of three-point support to align the work vertically in the ixture. One of the means for clamping the work into the fixture comprises a pair of bell cranks |44 which are pivotally supported on pins |45 carried by the rear wall of the fixture. The downwardly extending arms of these bell cranks have drilled holes |46 into which extends an equalizer bar |41 which has double tapered end portions |48 which fit into these holes and at the same time permit lateral movement of the bar |41 with respect to the plane of the bell crank. The bottom |09 is provided with a rearwardly extending lug |49 which engages the center of the member |41 and' rotates the bell cranks in a counterclockwise direction.

The other arms of the bell cranks are adapted to enter holes |50 formed in the side of the work as the work moves laterally downward and then by counterclockwise rotation of the bell cranks, the lower end of the work is forced against the positive stop |43.

One of the means for applying lateral pressure on the work comprises a guide bar |5|, which as shown in the plan View in Figure 7, has a double tapered lateral edge whereby its greatest dimension is in the middle at |52 and this bar is supported at each end by a pair of integral levers |52' which are pivotally supported on pins |53. The pins are carried by uprights |54 which are integral with the bottom |09 for movement therewith. The upper ends of the uprights are cut away to form a shoulder |55 which serve as abutments for the stop pins |51 carried by the levers |52. These levers are continuously urged in a clockwise direction by suitable spring pressed plungers carried by the lower end of the levers |52 and engaging the side of the bottom |09. When no work is in the fixture the guide bar |5| is rotated until the pins |56 engage the shoulders |55. As the work piece moves into the xture the guide bar serves to laterally urge the 'work towards the center of the xture by a yielding lateral pressure. Also, as the bottom |09 moves laterally downward the bar |5| serves to 'yieldably push the Work onto the positioning supports|26and against the positive stops |43.

A pair of clamping plungers |58 are slidably mounted in the top of the front wall of the nxture and these plungers are partially beveled on the end to provide a clearance for the work engaging surfaces |59. The other ends ci the plunger project into rectangular passageways |60 in which are slidably mounted shifter blocks |6|. These blocks have an upwardly extending rib |62 which lies at an angle of 45 degrees to the direction of movement of the block and these ribs engage a slot |63 formed in the underside of plungers |58. `Thus, as the .block moves, the plunger |58 is positively moved in or out. The blocks are connected to an actuating rack |64 which is shifted by a pinion |65 rotatably supported on a pin |66. A second pinion |61 integral with the rst pinion engages a vertically reciprocable rack plunger |68. As shown in Figure 13, the plunger |68 is continuously urged downward by a spring |69 which is interposed between a shoulder |10 formed on the plunger and a shoulder |1l formed in the bore in which the plunger slides. The block |6| is connected by a bolt |12 to the rack bar |64, but with lost motion in one direction because the head |13 of the bolt is free to slide in one direction in the enlarged hole |14. A spring |15 is interposed between the end of the rack bar |64 and the end of the block |6| whereby the block is continuously urged in a direction away from the end of the rack bar, but this movement is limited by the head |13 of the bolt |12.

The block |60 is connected by a bolt |16 to the end of the rack bar |64, but has lost motion in one direction due to the fact that a spring |11 1' is interposed between the head |18 of the bolt, and a bushing |19 fixed in the end of a hole |80 in which the head of the bolt slides. From this it will be seen that the spring |11 continuously urges the block |60 towards the end of the rack bar |64 and with the spring |15 continuously urges the block |6| in a direction away from the end of the rack bar |64. The block |60 is connected to the plunger |58 by the same means by which the block |6I'is connected to the plunger. It will be noted that the ribs |63 on the biocks are positioned on the same side of the plungers as shown in Figure 7. Therefore, when the gear |65 is rotated in a counterclockwise direction, the rack bar |64 moves toward the left and resiliently urges'the block |6| toward the left through the medium of spring v|15 and resiliently holds the block |60 toward the left through the medium of spring |11. When the rack |65 is rotated in a clockwise direction, the lost motion between the heads of the bolts and the rack bar |64 is taken up and the blocks are positively returned to Withdraw plungers |58.

The guide bar |5| is positively clamped against the side of the work by a plunger |8| which is slidably mounted in the front wall of the xture in alignment with the bar |5| when the same is in its lowermost position. The plunger |8| is provided with a lateral groove |82 into which nts a rib |83 on a slidable block |84. The block is connected to an actuating plunger |85 which is continuously urged downward by a spring |86 interposed between a shoulder |81 formed on the plunger and a shoulder |88 formed in the bore in which the plunger slides. The rib |83 extends at substantially an angle of 45 degrees to the direction of movement of the block whereby upon downward movement of plunger |85 plunger |8| will be moved inward into engagement with the Vrail |5| and upon upward movement of the plunger |85, the plunger will be retracted. A pair of backing up plungers |89 are reciprocably mounted in sleeves |90 which are fixed in the bottom portion of the frame of the fixture. These plungers have caps |9| secured to the end thereof which telescope the ends of the sleeve so as to prevent foreign material entering the bore of the sleeves and interfering with the operation thereof. The lower ends of the plunger are beveled for engaging beveled slots |92 formed in the top side of plungers |93. The plungers |93 are continuously urged toward the right, as viewed in Figure 6, by springs |94 which are interposed between the end of the plungers and the ends of the4 bore in which they reciprocate. When the fixture is down in the-position in which it is shown in Figure 6, the ends of the plunger |93 abut a plate |94 and are thereby reciprocated toward the left to permit the backing up plungers |39 to drop out of engagement with the work and permit the same to be properly positioned and clamped in the iixture without interference therefrom.

The fixture, as a whole, operates inthe following manner: After a new work piece has been placed in it, the operator rotates the handle |25 andthe cam ||4 is rotated in a direction to permit clockwise rotation of the operating lever ||2 for the drop bottom. A spring pressed plunger |95 is reciprocably mounted in a bore |90 as shown in Figures v6 and 7. This plunger engages the side of the drop bottom |09 and is continuously urging the same into a downward position, whereby it will be apparent that upon rotation of the cam I4 in a counterclockwise direction the bottom |99 moves laterally downward until the rearwardly extending lug |49 engages the equalizer bar |47, whereupon the force of plunger |95 is transmitted to the bell cranks |44 to cause rotation thereof into engagement with the work. It will be noted in Figure 2 that there is a clearance between the roller H3 and the cam which thereby prevents any interference to the action of plunger |95 in rotating the bell cranks and thereby insures that the necessary movement is imparted to the bell cranks to bring them into engagement with the work.

As the iixture starts its clockwise rotation into broaching position, four spring pressed plungers start to move relative to the fixture to eifect final clamping of the work. In other words, the plungers |93 start moving to kthe right relative to the fixture, as viewed in Figure 6, to raise the backing-up plungers I 89; the plunger |85 moves downward to advance plunger I8! into engagement with the back of the guide barv |5|; the plunger |58 starts to move downward to advance clamping plungers |59; and a plunger |91 starts to move downward to clamp the equalizing bar 539. As shown in Figure 6, the plunger |91 has a beveled face |98 which engages a beveled surface i90 formedon the equalizer bar |39, whereby downward movement of the plunger |97 clamps the equalizer bar |39 and thereby clamps the plungers I3? and |38.

When all of the plungers |97, |93, |85 and'l have completed their movements, the work is held in a clamped position by the plungers |59 and the plunger l 8 l, and the backing-up plungers 99 are in a position to prevent outward movement of the work under cut.

It will now be apparent that as the work lixture swings downward from its cutting position that the momentum of the iixture is absorbed in vcompressing the springs of the various actuating plungers as well as rotating the cam H4 against the resistance of plunger |95 whereby when the fixture comes to rest on the two supporting pedestals 200 and the work will be in a position to be moved out of the iixture.

Attention is invited to the fact that the plungers |85 and |68 have V-shaped ends which engage properly positioned vertical plates 202 and 203 which have inclined surfaces so as to engage the plungers as they execute their arcuate movement due to rotation of the fixture.

Power operable means have been provided for moving the work from the conveyor |08 into the iixture 22 and this means comprises a hydraulically operated plunger 204 which has a piston 205 attached to the end thereof and contained in a cylinder 206. inverted T-shaped arm 201 attached to the end thereof and this arm carries two work engaging ngers 208 and 209 and arranged one in advance of the other so that the forward one will pushthe finished work piece out of the fixture and the rearward one will pull a new work piece into the xture.

Referring to Figure 12, Yoperation of plunger 204 is controlled by a reversing valve 2|0 having a spring pressed plunger 2| E. pair of ports 2|2 and 2 I3 whichare connected by channels 2 |4 and 2| 5 to opposite ends of cylinder 206. Pressure is supplied to the port 2|9 of this valve by a pump 2|? through channel 2l8. The plunger 2I| is normally held in the position shown in Figure 12 by the spring 2|9, whereby the pressure port 2| 6 is connected to port 2|3 and the plunger 204 is in a retracted position. Upon rotation of a manually operable lever 220, having lan arm 22| in engagement with the end of plunger 2H, the latter is moved to connect port 2|6 to port 2|2 and thereby cause the plunger 204 to advance the work. Upon release of thelever 220 the plunger 2li automatically returns -to the position shown and causes retraction of the work pusher. f

A positive stopis provided against which the work is positioned by the work pusher, and thisy mechanism is shown more particularly in Figures '7 and 8. The stop member 222 has an elonrod 224 is fixed at opposite ends in the drop bottom |09 for movement therewith. y

The` member 222 also has a square slot 220 formed in the upper side thereof through which passes a second rod 221. A spring 228 is mounted in an angular boreformed in the member 222 and has one end iixed with the member and the other end fixed with the rod 22'?, whereby the spring continuously urges the member 222 in a counterclockwise direction about the rod 224 as a center. It will be noted that the spring also acts at the required angle .to normally urge the member 222 toward the right, as viewed in Figure `8, to thereby take up the lost motion between the two slots and the respective. pins pas-sing therethrough. It should now be evident that when the drop bottom |09 moves downward to such an extent that the shoulder 229 on the stop passes out of engagement with the end of the work piece, that the spring 220'is free to shift the stop member 222 toward .the right. This will occur automatically because the drop bottom |09 is lowered by rotation of the hand lever |25, as previously explained, after the work has been placed in the fixture; Since the stop mem- This valve has a The plunger has an l ber 222 is now retracted, it willy be evident that when the drop bottom frame |09 isautomatically raised by the plunger ||8 during counterclockwise return movement of the fixture to a loading position, the stop member 222 will come up under the work piece, and thus it will not interfere with the removal of the finished work piece, but as soon as the finished work piece has passed out of the fixture, the stop will move into position under the urge of spring 228 so that the next entering work piece will engage the shoulder 229 and thereby shift the stop member 222 toward the left until the face 230 on the stop member vengages the surface 23| on the drop bottom frame |09, which serves as a positive means for determining the position of the work.

It will now be evident that during downward movement of the drop bottom |09, the stop member is retracted a suiiicient amount that when the frame |09 is again raised the stop will not interfere with the present piece of work in the fixture but will reappear to stop the movement of the next work piece inserted in the fixture.

The fixture is held in a cutting position by a pivoted fixture lock 232. This lock is supported on a rod 233, which, as shown in Figure 2, is carried by the frame of the machine. It is moved up and down by a piston 234 which is slidably mounted in a cylinder 235 and connected by 'a piston rod 236 to the locking member.

The fixture is provided with two radially Yextending lugs 231 and 238 which have a straight face 239 on one side for engaging straight faces 240 formed on the frame of the machine and forming a fixed part of the locking mechanism. The other face. 24| of the lugr is tapered with respect to the face 239 for engagement by the tapered faces 242 carried by the lock 232. When the fixture has been swung clockwise into its broaching position with the faces 239 abutting the faces 240, the locking member is swung counterclockwise downward whereby the tapered faces 242 on the locking member Aengage the tapered surfaces 24| on the xture and thereby lock the same into its broaching position.

Located in bore 500 of `fixture lock 232 is a spring pressed plunger 50| having a cam surface 502 for engagement with cam surface 593 formed on lug 231, see Figures 9 and 10.

As fixture lock 232 swings downward into locking position the plunger 50| actuates the entire fixture 22 against the end stop 504 mounted on upright 505. In this manner the thrust of the cut is transmitted to the bed of the machine.

When fixture 22 is actuated downward or to the loading position, camv 506 on upright 505 engages cam 501 on the fixture to actuate same to the right as seen in Figures l and '1.

The admission of fluid pressure to the locking cylinder 235 is controlledby a reversing' valve 243 which has a pair of ports 244 and 245 which are connected by channels 246 and 241 respectively to opposite ends of the cylinder. This valve also has a pressure port 248 located between `ports 244 and 245 and a pair of exhaust ports 249 and 250. A spring 25| normally urges the valve plunger 252 of this valve into a position in 'which the pressure port 248 is connected to the port 244, whereby the lock is held in an upward or unlocking position.

'I'he fixture automatically effects its own locking which is accomplished by providing a pin 253 in the side of lug 231, whereby as the fixture reaches its final position it actuates a plunger 254 which is operatively connected by a bell crank 255 to the lock control valve 243 for shift- -ing the plunger 252 into a position connecting pressure port 248 to port 241. Fluid now flows to the upper end of cylinder 235, moving the piston 234 and connected lock 232 downward.

As the locking member 232 moves downward, a finger 256 rotates a trip lever 251, which, through an integral crank arm, 258, shifts a plunger 259 of an interlock control valve. This valve has a pressure port 260, a pair of ports 26| and 262 which are connected by channels' 263 and 264 respectively to opposite ends of an interlock valve 265. The valve also has a pair of return ports 266 and 261. In the position shown, the pressure port 250 is connected to port 26| and port 262 is connected to the return port 261, but upon rotation of the trip lever 251 in a clockwise direction, the pressure port 260 is connected to port 262, whereby the plunger 269 of the interlock valve 265 is shifted to a right hand position.

Valve plunger 259 also interconnects a pair of ports 269 and 210, whereby port 21| of the locking cylinder control valve 243 is connected through channels 212 and 91 to the interlocking lcylinder 95 associated with the breaching rami` control mechanism shown in Figure 11. Since the plunger 252 is shifted to the left, the port 21| is connected to a second pressure port 213 in valve 243, whereby the plunger 93 in cylinder 95 is shifted downward to rotate the interlocking bell" crank 9| out of locking position, permitting manual rotation of the hand lever 85 in a clockwise direction. This will shift the pilot control reversing valve 32, causing admission of fluid .pressure to the left hand end of cylinder 24 and thereby movement of the broaching ram to the left. When the ram reaches the end of its cutting stroke, a trip dog actuates the rack plunger 84 and shifts the pilot valve to a stop position, thereby stopping the ram. At the same time, a dog 214 shifts a spring pressed valve plunger 215 into a position interconnecting a port 2'i6 with a port 211. The port 216 is connected by channel 218 to a port 219 of the pilot valve 66. When the pilot valve isy shifted to a stop position, the

port 219 is interconnected with a pressure port The port 211 is connected by a channel 28| to an interlock plunger 282. Pressure actuation of 'this plunger removes a locking pawl 293 from engagement with a notched locking segment 284 secured to the shaft 285. The shaft 285 has a manually operated lever 286 secured thereto for :rotating the shaft and thereby cause shifting of a valve plunger 281 of a reversing control valve 288 for the indexing hydraulic motor 289. This valve has a pressure port 299' and a pair of motor ports 29| and 292, and a pair of exhaust ports 293 'and 294. The port 292 is connected by channel draulic motor 289.

The port 29| is similarly connected to the other port of motor 289, there being an interlock valve 303 and a check valve 304 which have ports 305 and 366 respectively connected by channel 301 to 'port 29|; and ports 308 and 309 respectively connected by channel 3|0 to motor port 3| Since additional interlocks must be removed before the lever 286 can be operated to effect actuation of the motor 289, further description of the control mechanism for the motor will be deferred for the present.

Upper work fixture The upper work fixture 23 is fixed for rotation with shaft SI2 which is journaled at opposite ends in uprights 313 and 3M. This shaft has a gear segment 3i5 fixed to one end thereof, and as shown in Figure 3, this gear segment intermeshes with a gear segment 3|8 which is keyed to the motor shaft mi. Since the lower fixture is directly moved by the shaft IUI, itwill be apparent that upon rotation of the shaft, one fixture will move clockwise While the other fixture is moving counterclockwise. The two fixtures are connected to the shafts in a 90 degree phase relationship, whereby when one fixture is in` a cutting position the other fixture is in a loading position and vice versa.

'I'he upper fixture has a plain work receiving surface 3|? as shown in Figure 2 for supporting the Work and it will be noted that the top surface of the work which was finished in the .first broaching operation serves as the supporting face of the work when it is transferred into the second fixture.

When the work moves into the fixture it engages an end stop 358 which is normally held up into a stop position by a spring pressed plunger 3|3 acting at an angle of 45 degrees and a fixed plate 323 is provided for limiting the upward movement of the end stop, as well as taking the thrust of the endwise movement of the Work when it engages the stop. As a matter of fact, the member 32B serves as a fulcrum for the end stop, the work tending to rotate it in a counterclock-r wise direction, but the heel 32 i, located below the member 323, prevents this rotation.

When the fixture moves upward to cutting position a pin 322 is fixed in` the upright 383 in a position to engage the end stop just before the fixture reaches its final position and moves the same longitudinally until the end stop is below the underside of the work piece, whereby the spring pressed plunger will rotate the stop about the bar 32B and due to the reduced portion 323, the end stop will rotate to a position underneath the work, whereby when the fixture is returned to a loading position the work piece maypass out of the iixture without interference from the end stop.

The lateral position of the work is determined by a fixed rail 323 positioned to engage the side of the work piece near the top thereof.

The work is clamped to the surface 3H by four clamps 325 which are pivotally supported on the fixture and positioned to engage portions of the iiange 323 of the work, there being two clamps on each side of the work and located near the ends thereof. Four actuating rods 32?, 323,

' ber 333 also has a certain amount of lateral lost motion so as to equalize the pressure between the pair of clamping members at one end of the xture. In this manner the pressure of all four clamps is equalized. The rack member 335 and a second rack member 33B which actuates the rods 329 and 333 through the same cam mechanism interengage a pinion 331 which is rotatably mounted in the center of the fixture and in mesh with a rack bar 338 which extends at right angles to the rack bars'335 and 336. A spring 339 is mounted in a blind hole behing the rod 338 to continuously urge the same in a direction to eifect clamping.

A cam 343 is rotatably mounted in the fixture opposite the end of rack bar 333 on a shaft 34|. r)Phe shaft extends beyond one end of the fixture and is provided with an operating handle 342. The shaft 34H has a pinion 343 which intermeshes with rack teeth formed on a rod 333 which is normally urged in one direction by a spring 345. This mechanism is similarV to the, mechanism shown in the first fixture and the end of the rod 363 is provided with a roller 346 whereby as the fixture comes down to a loading position, the end of the rollerwill impinge on the edge of a plate 341 and thereby compress the spring 335, causing rotation of the cam 340 and longitudinal movement of the rack bar 333 against the compression of spring 333 to effect release of the four clamping members 323. Due to the tongue and groove connection between the actuating rods 321 to 339,

inclusive, and the operating cams 333, the rods will be positively retracted by rotation of the cam 336 in a counterclockwise direction.

After the iinished work has been removed, and a new work piece has been inserted, the operator actuates the handle 332 to rotate the cam 343 in a clockwise direction, thereby permitting the spring 333 to actuate clamps and securel the Work.

Since the work is being breached on two right angular surfaces, while in this fixture, a pair of backing-up plungersiti' and 338 are provided in the wall of the fixture between the rail 32d and the bottom of the xture to take the thrust of the broaching teeth 23.' These stops have tongue and groove connections with actuating rods 349 and 353 supported for reciprocation in right angular relation to the movement of members34'l and 333 and springs 35i are interposed behind the rods 349 and 350 normally urging them in a direction toward the work. When the fixture moves counterclockwise downward to a loading position, cam blocks 352 are provided on the sides of the uprights 3&3 and 3M to cam the members 349 and 350 toward one another and thereby positively withdraw the backing-up stops 341 and 333, whereby the work may be changed without interference therefrom.

A plunger for actuating fixture 23 against stop 538 is similar to plunger in locking member 232 and, thereforeis not shown in detail.

It will now be apparent that, as in the first fixture, the kinetic energy of the moving fixture as it returns to loading position is utilized to effect unclamping of the work and in so doing, loads a spring which may be subsequently released at the will of the operator to reclamp the work. n

Work roll-over mechanism Means have been provided for transferring the work from one fixture to the other and at tho same time turning the work over so that the surface which was broached while the work was in the first xture is utilized as a Supporting surfacefor the work while in the second fixture, whereby other surfaces on the work, which were inaccessible while lthe work was in the first vfixture, may be broached. Referring to Figures l and 3, a work receiving cage 333 is sup-ported on the end of a shaft 354 and in eccentric relation thereto whereby when the cage is in the position shown in Figure 3 the top surface of the rollers 355 are substantially in the plane of the rollers of the iirst fixture 22, whereby work may be readily transferred from one to the other.

A second set of rollers 356 is provided in the cage and located co-axially with the axis of shaft 354, whereby upon rotation of the cage, the work will be supported on the top of the rollers 356 and substantially in the plane of the second fixture for transfer thereto.

As viewed in Figure 1, the cage 353 is rotated in a countei'clockwise direction from its lower position to its upper position. In order to prevent the work falling out of the xture while it is being rotated, a large plate 351 is attached to one end of the cage. The cage is rotated by the same motor that rotates the fixtures and to this end the shaft 354 is provided with a spiral gear 358, which as is shown in Figure 4, intermeshes with a spiral gear 359 keyed to shaft 360. This shaft has a bevel gear 36| secured to the end thereof which intermeshes with a partial bevel gear 362 xed with shaft 354. Since the cage is integrally connected with the shaft 354 it will be apparent that it rotates in synchronism with the iixtures and is so connected that it is in its lower position when the iirst fixture is in a loading position, and in its upper position when the second fixture is in its loading position.

Power operable means are provided for transferring the work from the cage to the second fixture and comprises a piston 363 contained in a cylinder 364 and connected by a piston rod 365 to an inserted T-shaped arm 366 which carries at each end a pair of work engaging lingers 361 and 358. The iingers are sufficiently spaced so that when the piston is moved to its extreme right hand position the ringer 368 will engage the work piece that is in the cage and the riger 361 will engage the work piece that is in the fixture 23; whereby upon movement of the piston 363 to the left, the nished work piece will be removed and a semi-finished lwork piece will be inserted in the fixture. The nished work piece passes out onto a conveyor 369 which is located in the plane of the floor of the iixture 23 when the same is in a loading position.

Operation of piston 363 is controlled by a valve 310 having a plunger 31| which is normally positioned by a spring 312 in a position to connect a pressure port 313 to port 314 which is connected by channel 315 to the right hand end of cylinder 364, thereby holding the cylinder 363 in its extreme position. A lever 316 is pivotally mounted at 311 in such a position that the end of the lever engages the end of a plunger and a stop 318 is provided to limit the outward movement of the plunger by spring 312. A manually operable handle 319 is attached to the lever for rotating the same to cause movement of the plunger 31| against the action of the spring and connect pressure port 313 to port 380 which is connected by channel 38| to the left end of cylinder 364.

When the operator actuates the lever 319 to shift plunger 31| and thereby connect pressure fluid to the left hand end of cylinder 364, the piston 363 moves toward the right and the work engaging fingers 361 and 368 are free to move in a clockwise direction about the pivot pins 382 as they pass over the work pieces that are in the iixture and in the roll-over cage. The iingers are mounted in bifurcations whereby a shoulder 383 is formed for preventing counterclockwise rotation of the finger 361 and a spring pressed plunger 384 normally holds the linger against this shoulder. The finger 368 is normally held in the position shown by a spring pressed pawl 385 which engages a notch 386 formed in the top of the finger 368, the notch having a shoulder 381 which engages the pawl and thereby prevents counterclockwise rotation of the nger after it engages the work. The notch is so shaped that after clockwise rotation, as when the ringer is rotated by the work during movement toward the right, the pawl will reset the iinger in proper position to engage the work. The pawl 385 is pivoted at 388 and is provided with an elongated tail 389 in the end of which is mounted a pin 390. A spring pressed plunger 39| continuously acts to rotate the pawl 385 in a clockwise direction to cause engagement of the nose of the pawl with the notch 386. When these parts are in contact the tail 389 is up as shown in Figure 15, and this is the position of the parts when the work pushers start moving the work toward the left. When the work piece hits the positive stop in fixture 23 the pin 390 engages a cam surface 392 and rotates the pawl 385 in a counterclockwise direction, thereby releasing the linger 368 so that the parts can continue their movement to a position which is out of the path of the iixture when it rotates upward to a cutting position. Since the head 366 is attached to the end of the piston rod 365, means have been provided for preventing rotation of the parts comprising a rectangular bar 393 which is attached to the top of the head 366 above the piston rod and this bar is slideable in guides 394 and 395 ixed with the cylinder.

It will now be apparent that by rotating the lever 319 the operator can cause power movement of the parts to pick up two work pieces and then by releasing the lever, the spring 312 returns valve 31| to a position to cause movement of the work pusher to the left and during that movement the linger 368 is automatically released when the work engages the parts to stop so that the work f.

posite ends connected by channels 40| and 402 to" a reversing control valve 403. This valve is operated by a plunger 404 and intervening bell crank 405, whereby when the ixture 23 reaches a cutting position it will shift the plunger 406 of valve 405 and thereby reverse the pressure connections to valve 403 to cause downward movement of piston 391. The lock member 399, as it moves downward, operates a double-ended trip lever 401 which is operatively connected to a valve plunger 408 of valve 409 to thereby connect a pressure port 4|0 to channel 4|| which operates the interlock valve 303.

When pressure is connected to the upper end of cylinder 400 to actuate the lock 399, a connection is made through channel 4|2 to an interlock cylinder 4|3 which has a plunger 4|4 movable under the hydraulic pressure to remove a latch lever 4|5 from the path of control lever 22| of valve 2|0, This lever, which is operable by handle 220, controlst the' work loading piston 205 for the first fixture.. Thus, when the second xture islocked in cutting position, the first fixture will, of course, be down in a loading position, and since the interlock 4|5 has been removed, it is possible for the operator to load the first xture during the time that the broaching operation is being performed on the work in the second fixture. Also at this time the work roll-over cage 353 will be in its lower position as shown in Figure 3 so that not only is a new work piece loaded in the first fixture but the seminished work piece in the rst fixture is simultaneously loaded into the cage 353.

When the piston 205 starts its reciprocatory movement it is supporting in raised position an interlock valve plunger 4|6 which is continuously urged in one direction by a spring 4|? so that when the cam surface 4|8 moves from under the plunger, said plunger is shifted downwardly to connect channel 4|9 leading from an interlock cylinder 420 to the reservoir line 42|. The result is that a pawl 422 which has been held out of engagement with the interlock plates 284 by plunger 423, which is mounted in the cylinder 420, is returned to locking engagement with the interlockplate by a spring 424. It will be remembered that the member 284 is secured to the shaft 285 which has the operating handle 286 for shifting the reversing valve of the fixture motor withthe result that it will be impossible to operate this valve duringthe loading of the xtures.

Since the second fixture is in a cutting position, means have been provided for preventing the operation of the second work loading mechanism, and therefore, the upper end of cylinder 235 is connected by channel 425 to an interlock cylinder 426 which has a plunger 421 operating on an interlock pawl 428. Ar spring 429 continuously urges this pawl into-interlocking engagement with the end` of lever 316, and therefore, when the upper end of cylinder 235 is connected to exhaust no pressure will be present in cylinder 426 and the interlocking kpawl can move into position underthe action of spring 429 to prevent actuation of lever 316 and thereby prevent actuation of the work loading mechanism of the second fixture while the second fixture is in cutting position.

A.It will be obvious that when pressure is admitted to cylinder 235 to lock the first fixture in cutting position that pressure will be present in channel 425 and the interlock will be removed from the -control valve 318 so that the second work loading mechanism may be operated while the work in the first fixture is being broached.

When the second work loading mechanism is being utilized, a hydraulic interlock valve 430 is provided so that during advance and retraction of'piston 363, the valve plunger 43| will be moved downward under a spring 432 to connect channell 433 to reservoir line 434. The channel 433 leads to cylinder 435 in which is reciprocably mounted a plunger 435 for removing an interlock pawl 431 from the segment 284. When the channel 433 is connected to reservoir, a spring 438 returns the pawl 431 into locking engagement with the member 284. It will now be apparent that three different interlocking pawls are mounted in adjacent relation to the interlocking segment 284 fixed on the shaft 285 so that if any one of these hydraulic motor.

Operation ofv the machine The operation ofv the machine will be briefly summarized, and assuming as a starting pointv rthat the various parts are in the position shown in Figure 1, thatv is, with the second fixture in a cutting position, the first xture in a loading po- ,y

sition, the work roll-over cage 353 in itslower terlock plunger 94 and removing the interlock 2,9:

bell crank 82 as shown in Figure 11. This permits the operator to throw the manual control lever 85 in a counterclockwise direction and thereby connect pressure port 10 to port 64, thereby shifting the reversing valve plunger 38 upward so thatthe right hand end of cylinder 24 is supplied with pressure through the interconneo` tion of port 33 and y3| and the left end of` cylin-v der 24 is connected to reservoir through the'in-l terconnection of ports 30 and 31. This will cause movement of breaching ram i3 to the right as viewed in Figure 1.

The breaching ram starts toV move and dog ,214, l

passes out from beneath plunger 215, whereby a spring 443 shifts the plunger 215 rdownward to interconnect channel 28| to the reservoir line 444. Channel 28| is connected to the interlock plunger 282 and since this is now connected to reservoir, a spring 445 moves the interlock pawl 283 into engagement with member 284. Thus, as soon as the ram starts to move, an interlock isap-v plied to the xture motor control valve to prevent inadvertent actuation thereof.

During the broaching stroke the interlock has been removed from lever 220;'whereby the work loading mechanism associated with the first fix--y ture may be utilized to remove the Work from the first fixture into the cage and advance a new work piece from the conveyor into the first fixture.

When the breaching ram reaches the end 0f its cutting stroke, a dog will shift the rack plunger 83, shown in Figure 1i, upward, thereby returning the pilot valve 12 toa central position vmember. 284, whereby the hand lever 284i:` may now be actuated vto shift the reversing valve plunger 282. At this time, the plunger 281 will be shifted toward the right from the position shown in Figure l2 and thereby interconnect pressure port 290 to port 23|. Since the plungers of both the interlock valve 343 and the relief valve 304 are in a position to block flow to the fixture motor 289, the pressure will buildup in channel 301 to` act through branch line 441 on the left hand end of plunger 408 of reversing valve 403 which, at this time, is being held in a left handposition by the iixturev 23. It will be noted, however. that there is a lost motion connection between the plunger 405 and the operating bell crank 405. This lost motion connection permits the plunger 406 to' be shifted toward the right to thereby connect pressure port 448 to port 449 which is connected by channel 592 to the lower end of cylinder E). Also, ports 459 and 35i are interconnected so that channel 49! leading from the upper end of cylinder 4539 is connected to the reservoir line 452. This not only permits the fluid from the upper end of cylinder 496 to be exhausted to reservoir, but also connects the interlock cylinder 4 i 3 to reservoir, whereby a spring 453 will reposition the interlock pavvl l i5 and prevent actuation of the control lever 229 for the work loading mechanism of the first fixture.

Piston 391 now moves upward, unlocking the fixture 23 and at the end of this upward movement, throws the trip lever '461 and shifts valve plunger 438 to the right. When valve plunger 456 was shifted to the right it connected port 443,

which led to the interlock plunger 94, to reservoir port 454, thereby replacing the interlock bell crank 92 shown in Figure ll; and when the plunger 493 is shifted to the right it disconnects port 442 from port 44h-whereby the interlock plunger' 94is now disconnected from the circuit.

In addition, when plunger 498 is shifted to the right it connects the pressure port 4I@ to port 455, thereby shifting the plunger of interlock valve 393 to the right and effecting interconnection of ports 395 and 303, whereby pressure fluid in channel 361 may now flow to the hydraulic motor 289. This motor is a vane type motor and is similar to that shown in co-pending application, Serial Number 152,200, filed July 6, 1937. When pressure is admitted to this motor the vane 456 moves counter-clockwise and since it is attached to the end of shaft lill, the shaft ll will rotate counterclockwise, thereby moving the fixture 22 upward to a cutting position; rotate the cage 353 to its upper position; and rotate the fixture 23 downward to a loading position.

As soon as the fixture 23 starts to move downward, the pressure on the right hand end of the plunger is released, but the plunger is already in a right hand position with the result that When the pressure is cut off from channel 441 it will still remain in that position.

VAs fixture 23 is moving down, fixture 22 is moving up due to vthe rotation of the hydraulic motor and'near the end of its upward movement will shift the valve plunger252 to connect pressure port 248 to port 245 and thereby cause downward movement of the locking lever 232. Admittance of pressure to channel 241 also supplies pressure to cylinder 426, thereby removing the interlock on control lever 319 which permits operation of the work ejecting mechanism associated with the second fixture. 'Ihe lower end of cylinder 235 is connected to reservoir through the end connection of ports 241i and 249. is also interconnected with yport 21|, thereby rendering port 259 associated with valve plunger 259 a pressure port, whereby upon shifting of this plunger, upon completion of the movement of locking lever 232, this port will be connected'tochannel 91 to actuate plunger 93 and thereby remove the interlocking bell crank 91 from the ram starting lever. of plunger 259 to the right interconnects pressure port 260 to port 262 and thereby shifts the interlocking plunger 258 to the right, disconnecting port 299 from 296 whereby the return flow from the hydraulic motor is blocked to stop rota- Port 213V At 'the same time, shifting tion of the motor. The relief valve 298 connected` in parallel with the interlock valve 265 permits a slight additional movement of the motor in case the fixture is not solidly against the pads 240.

Since the interlock plunger 91, shown in Figure il, has been removed, the operator may now shift the lever 85 to the left to cause return movement of the breaching ram to effect cutting of the work in fixture 22.

What is claimed is:

i. In a breaching machine having a surface breaching tool and a swinging work fixture movable from a loading position to a cutting position, the combination of resiliently operable work clamping means carried by the fixture and operable to secure a work piece in position in 'the fixture during the broaching operation, and means responsive to movement of the fixture to a loading position for compressing said resiliently operable means and thereby releasing the work.

2. In a broaching machine having a broaching tool and a Work supporting fixture movable from a loading position to a cutting position, the combination of a plurality of pivoted work clamping members carried by the fixture, resilient means for holding said clamping members in engagement with the work, and means to utilize the kinetic energy of the moving fixture for releasing said clamps.

3. In a breaching machine having a Work supporting fixture movable from a loading position to a cutting position, the combination of a plurality of positioning andclamping means carried by the xtiue and operable to secure a work piece in position in the fixture during the breaching operation, means to utilize the potential energy of the fixture while in a loading position to hold said means retracted in order to permit loading of Work in the fixture, said means being releasable after a predetermined movement of the fixture whereby the work will be clamped during movement of the fixture from a loading to a cutting position. i

e. In a broaching machine having a broaching tool and a work supporting xture movable from a loading position to a cutting position, the combination of means in the fixture for clamping the Work, a plurality of jacks mounted in the fixture for kabsorbing one component of the cutting force of the broaching tool, and means for automatically positioning said jacks during movement of the fixture to its cutting position.

5. In a broaching machine having a broaching tool and a work fixture movable to and from a cutting position with respect to said tool, the combination of fluid operable means for locking said fixture in its cutting position and absorbing one component of the cutting force, a fixed member positioned to be engaged by the work for absorbing the Vother component of the cutting force, and means operable by the locking means for shifting said fixture to effect engagement of the work with said fixed member.

6. In a broaching machine having a breaching tool and a work fixture movable from a loading position to a broaching position, the combination with an hydraulic motor for moving said fixture and a power operated Work loader for said fixture, of an interlock to prevent operation of said motor during actuation of said Work loader.

'1. In a broaching machine having a broaching tool and a work supporting fixture lmovable means for moving said fixture, means to lock said `"5 

